Lens assembly and a camera module including the same

Abstract

The lens assembly may include a housing, a first group lens assembly disposed in the housing, and a second group lens assembly disposed at one side of the first group lens assembly. The first group lens assembly may be a fixed lens assembly, and may include a first lens and a liquid lens. The second group lens assembly may be a movable lens assembly and may include a second lens group. The first group lens assembly may have a negative (−) refractive power as a whole, and the second group lens assembly may have a positive (+) refractive power as a whole.

The invention claimed is: 
     
         1 . A camera module comprising:
 a lens assembly comprising:
 a first group lens assembly; and 
 a second group lens assembly disposed on one side of the first group lens assembly; 
   a housing where the first group lens assembly and the second group lens assembly are disposed; and   an image sensor disposed on one side of the housing,   wherein the first group lens assembly comprises a first lens group and a liquid lens,   wherein the second group lens assembly comprises a second lens group,   wherein an optical system constituting the first group lens assembly has a negative refractive power,   wherein an optical system constituting the second group lens assembly has a positive refractive power,   wherein the liquid lens is disposed between the first lens group and the second lens group,   wherein each of the first lens group and the second lens group comprises a plurality of lenses,   wherein the first lens group comprises a first lens and a second lens, each of the first lens and the second lens comprising a plastic lens or a glass lens,   wherein the second lens group is a moving lens group and comprises a third lens, a fourth lens, a fifth lens, and a sixth lens, each of the third lens, the fourth lens, the fifth lens, and the sixth lens comprising a plastic lens or a glass lens,   wherein each lens in the first group lens assembly has a fixed position with respect to an optical axis direction,   wherein the moving lens group of the second lens group is disposed between the first group lens assembly having the fixed position and the image sensor without another interposed fixed lens group being located between the moving lens group and the image sensor,   wherein a first surface of the second lens of the first lens group contacts the liquid lens and a second surface of the second lens opposite the first surface of the second lens does not contact the first lens of the first lens group,   wherein the first surface of the second lens of the first lens group that contacts the liquid lens includes a concave surface such that edge portions of the first surface the second lens contact the liquid lens but a central portion of the first surface the second lens does not contact the liquid lens, and   wherein the second surface of the second lens opposite the first surface of the second lens includes a concave surface.   
     
     
         2 . The camera module according to  claim 1 , wherein the liquid lens comprises a first liquid and a second liquid that form an interface with each other. 
     
     
         3 . The camera module according to  claim 2 , wherein the liquid lens performs an auto focusing (AF) function by adjusting a shape of the interface, and performs zoom by adjusting a physical position of the second lens group. 
     
     
         4 . The camera module according to  claim 1 , further comprising a coil,
 wherein the second group lens assembly comprises a lens barrel in which the plurality of lenses are disposed and a magnet disposed in the lens barrel, and   wherein the coil faces the magnet.   
     
     
         5 . The camera module according to  claim 1 , wherein an aperture size of the liquid lens is less than that of the first lens group. 
     
     
         6 . The camera module according to  claim 5 , wherein the liquid lens comprises a first liquid lens containing a first liquid, and a second liquid lens containing a second liquid that is not mixed with the first liquid, a first plate sealing an object side of the first liquid lens and a second plate sealing an image side of the second liquid lens. 
     
     
         7 . The camera module according to  claim 6 , wherein the first liquid or the second liquid comprises a conductive or polar liquid, and a curvature radius of a liquid interface formed between the first liquid and the second liquid is changed according to an applied voltage. 
     
     
         8 . The camera module according to  claim 6 , wherein the first liquid lens and the second liquid lens comprise a flat lens surface at a wide position. 
     
     
         9 . The camera module according to  claim 1 , wherein the first lens of the first group lens assembly comprises a positive refractive power, and
 wherein the second lens of the first group lens assembly comprises a negative refractive power.   
     
     
         10 . The camera module according to  claim 1 , wherein the third lens of the second lens group comprises a positive refractive power,
 wherein the fourth lens of the second lens group comprises a positive refractive power,   wherein the fifth lens of the second lens group comprises a positive refractive power, and   wherein the sixth lens of the second lens group comprises a negative refractive power.   
     
     
         11 . The camera module according to  claim 1 , wherein a first group lens assembly-side surface of a lens disposed closest to the first group lens assembly among the plurality of lenses of the second lens group is a convex surface. 
     
     
         12 . The camera module according to  claim 1 , wherein a distance between the first group lens assembly and the second group lens assembly is narrower toward a telephoto angle. 
     
     
         13 . The camera module according to  claim 1 , wherein a value of Fno (TeleFno) at a telephoto position/Fno (WideFno) at a wide-angle position is greater than 1. 
     
     
         14 . The camera module according to  claim 1 , wherein the first lens of the first lens group includes a concave surface and a convex surface. 
     
     
         15 . The camera module according to  claim 1 , wherein a focal length of the first lens of the first lens group is greater than a focal length of the second lens of the first lens group. 
     
     
         16 . The camera module according to  claim 1 , wherein a refractive power of the first lens of the first lens group is greater than a refractive power of the second lens of the first lens group.